Carbureting device for lighting stoves



Nov. 8, 1932. w. oLsEN ET AL 1,886,420

GARBURETING DEVICE FOR LIGHTING vSIOVES Filed June 7, 1928 Patented Nov.8, 1932y taten i; ot-Fi iii WALTER OLSEN AND SOPHUS RASMU'SSEN, 0FALBERT LEA, MINNESOTA CARBURETING DEVICE FOR LIGHTING STOVES lApplication filed June 7, 1928.

This invention relates to devices, such as stoves, lanterns, irons,heaters etc., using a liquid hydrocarbon fuel such as gasoline, which isvaporized and burned, and it relates particularly to what may be termedinstant lighters for such devices. Such devices utilizing a liquidhydrocarbon fuel which is vaporized and burned, are now used in largenumbers and prior to an invention 'i0 by John E. McCutchen upon which aUnited States patent has recently issued No. 1,718,- 473, dated June 25,1929, entitled Gil burning device, it was the common practice in suchdevices, when initially lighting the same, to heat a vaporizing memberto which liquid fuel was supplied either by burning a small quantity ofthe fuel under the vaporizing member in a priming cup, or byholding atorch under the vaporizing member for a short time. The McCutcheninvention eliminated the necessity for preheating the vaporizing member,in initially lighting the device, as just described, but this McCutchendevice is open to certain serious objections. In the McCutchen device,there is provided a burner, the flame -from which .plays on to avaporizing tube Within which'l-iquid fuel is adapted to be vaporized forsupplying the requirements of the burner. A tank containing liquidhydrocarbon fuel and compressed air is also provided and into'this tanka-main tube extends having a Small orifice located below thc liquidlevel of the tank. A branch tube is also located in the tank and thisbranch tube has an open upper end located Within and freelycommunicating with the air space of the tank and the branch tube has alower end communicating with the main tube adjacent the orifice there-43 in. A valve controls the main tube and a Conduit runs from this tubeto the vaporizing tube of the burner.A The orifice in the main tubelocated Within the tank is proportioned relative to the outlet end ofthe vaporizing 43 tube, so that as the Valve is opened, a small quantityof liquid fuel will flow in a regulated stream into the tube in thetank, While at the same time a stream of compressed air from the top Aofthe tank will flow from the 3 branch tube into the main tube iii thetank Serial No. 283,579.

' to mix with the liquid fuel and supply aimxtube located in the tank.This back pressure, according to McCutchens theory, slows up the flow ofliquid and air through the main tube in the tank, permitting the liquidfuel to flow up through the orifice into the main tube and through theconduit and the vaporizing tube to supply the burner de mand and closethe outlet of the branch tube 1n the tank to the main tube therein toseal o ff the air supply. As a lnatter 0f fact, in this Mc- Cutchendevice, this air supply to the main tube is never completely cut off aslong as any considerable pressure remains on the air in the tank. It istrue that as the Vaporizng tube is heated so that the liquid fuelsupplied to the vaporizing tube is vaporized, that the passage of airfrom thebianch tube to the main tube in the tankis checked, but it islikewise true that small quantities of air from the top of the tank willconstantly pass to the main tube in the tank and thence to the burner aslong as the burner remains in operation. In other Words, as long as theburner remains in operation, the supply of compressed air in the tankwill be constantly depleted. rlhis necessitates the renewal of thesupply of fresh air in the tank at frequent intervals, if the burnerwhich is instantly lighted Without preheating the gen-` erating tubesupplying the same, is to be kept in continuous operation.

We have discovered that if the passage through the orifice in the maintube located in the tank can be suddenly enlarged after the burner hasbeen initially ignited and after the vaporizing tube has been heated,liquid fuel will run intothis main tube in the tank in such quantity asto completely seal Off the passage supplying air from the y conduitsupplying the same and the main top of the tank to the main tube in thetank and thereby completely prevent the escapeof compressed air from thetop of the tank by way of the burner to eliminate the necessity forrenewing the supply of compressed air in the tank at frequent intervalsduring the continuous operation of the burner. The passage through theorifice in the main tube of the tank must be enlarged only after thevaporizing tube supplying the burner has been heated. If the passagethrough the oriice were made large enough to accomplish this air sealingfunction after the vaporizing tube had been heated and if the passagethrough the orifice was of the same size prior to the time that thevaporizing tube was heat ed and when the cold burner was initiallyignited, no air would be supplied with liquid fuel to the vaporizingtube to produce an initial combustible mixture which could beinstantaneously lit and the burner could not be lit without firstpreheating the Vaporizing tube as by a torch or by burning a smallquantity of liquid fuel in a cup underneath the vaporizing tube.

It is the main object of this invention, therefore, to provide aninstant lighting structure of the class described and wherein thepassage through an orifice in a tube located within the liquid space ofa tank containing liquid fuel under air pressure, can

` be suddenly enlarged.

A more detailed object is to provide means for cleaning such an orifice.

Another object is to provide a novel, improved simple, inexpensive andefficient lighting structure for devices, such as stoves, lanterns,irons, heaters etc., utilizing a liquid hydrocarbon fuel which isvaporized and burned.

These and other objects and advantages of the invention will be morefully set forth in the following description, made in connection withthe accompanying drawing, wherein like reference Characters refer tosimilar parts throughout the several views and in which Fig. l is apartial plan view of the stove having the invention applied thereto;

Fig. 2 is a 'vertical section taken on line 2 2 of Fig. 1 as indicatedby the arrows;

Fig. 3 is a vertical section taken on line 3-3 of Fig. 1 as indicated bythe arrows;

Fig. 4 is a vertical section taken on line 4 4 of Fig. 3 as indicated bythe arrows and Fig. 5 is a view similar to Fig. 4, showing amodification.

Referring to the drawing, a stove is shown comprising a top plate 10secured to and supported by a frame 11 shown as rectangular in form andextending downwardly from said .top plate, said top plate being securedby screws 13. A fuel tank 14 is supported at one end of the frame 11,being secured thereto by straps 15 secured to said frame. The

stove comprises one or more main burners 16 disposed below openings intop plate 10 and connected to a mixing chamber 17 secured to the topplate by screws 18. A vaporizing member or tube 19 connects with mixingchamber 17 and extends over one of the burners 16 as shown, said tubehaving valves for opening and closing the same operated by hand wheel20. Said tube 19 is connected to the .fuel tank by a small conduit ortube 21 connected to a fixture 22 secured to tank 14, which fixturecarries a pressure gauge 23 for indicating the pressure in the tank andalso comprises a valve 24. An auxiliary burner 25 is provided, andalthough this burner may` be used independently of burner 16, it isshown as forming a starting burner for heating tube 19, and while thisburner may be variously located, in the embodiment of the inventionillustratcd it is shown as disposed below tube 19 and between burners 16and mixing chamber 17. The burner 25 comprises a mixing chamber havingan open upper end 25a into which projects a fuel supplying andvaporizing tube 255 which is of quite small size. The mixing chamberalso has an opening 250 forming the ignition opening disposed below tube25?). Tube 25o connects with a valve body 26 having a valve seatadjacent one end engaged by a valve formed on the stem 27 which isoperated by the hand wheel 28. Valve body 26 has a depending lug towhich is secured a rod 29 forming a support for the mixing chamber ofburner 25. The part connecting burner 16 with mixing chamber 17 has apan 17a disposed below the opening 250 to catch any fuel overiowingtherefrom and to guide the same to said mixing chamber 17. A conduit 30connects valve body 26 to the fuel tank 14 and this conduit is connectedto a valve body or fixture 31 secured in the top of tank 14 by beingthreaded into a plug 32 secured in said tank. A tube 33 is secured tovalve body 31 within tank 14 and extends downwardly therein so that itslofwer end is disposed adjacent the bottom of said tank and in the fuelin said tank. Tube 33 is connected at its lower end to another tube 34surrounding and spaced therefrom, which tube 34 has an open upper enddisposed in the air space in tank 14. Tube 33 has a plurality ofcomparatively small openings 33a therein adjacent its lower end.affording communication with theinner side of tube 34,-. A plug 35 isthreaded -Into tube 33 and has a small central opening therethroughwhich is tapered at its lower end, whichopening communicates with theopening in tube 33. The shell 36 is threaded on the bottom of the tube34 and projects downwardly from the same, having a cylindrical openingsurrounding plug 35 and having a screen 37 extendng across its lowerend. A valve stem 3S is threaded in member 31, having an operating abouthalf a turn.

38 has a valve 38a closing communicaton' with tube 33, said stem having`a projecftion 38?) extending therefrom downwardly through member 31 andtube 33, said portion 38?) having a reduced needle 380 projectingdownwardlyl through the opening in plug 35, needle 38e having a conicalpointed end.

ln operation, when the stove is cold and not in operation, all thevalves are closed. `When the stove is to be started, valve 27 is openedand valve 38a is raised from its seat for a short distance by turningwheel 39 This initial turning movement of valve 38a and the valve stem38 is not sufficient to withdraw the needle 380 upwardly from the lowerend of theplug 35 sufficiently to materially increase the size of thepassage through the plug As a result, but a very small passage throughthe plug 35 to the tube 33 will be initially provided, this passagebeing preferably slightly larger than the passage through the outlet endof vvaporizing tube Q56. A certain amount of gasoline or fuel will nowpass through the needle obstructed opening in plug 35 into tube 33 andat the same time compressed air from the top of the tank 14 will besupplied to the tube 33 through tube 34 and opening 33a. The air runninginto tube 33 mixes with the liquid fuel in this tube and passes throughthe tube and out through conduit 30 into vaporizing tube 25?) and thenceinto the mixing chamber of burner 25 from whence it issues through theopening 250, where it can be instantly ignited with a match or otherlighting device. 0f course, liquid fuel from the tank 14 tends to movethrough the passage in plug 35 by reason of the difference in levelsbetween the surface of the liquid fuel in the tank and the bottom ofplug 35. The air pressure on the surface of the liquid fuel within thetank 14 is practically the same as the air pressure within the tube 33at this time, because communication is afforded between the air at thetop of the tank and the tube 33 through the tube 34 and air openings33a. The restricted passage in the plug 35 offers considerablefrictional resistance to the travel of liquid fuel into tube 33 throughthe same and only a small quantity of liquid fuel will enter the tube 33through this passage. This small quantity of liquid fuel will beentrained by theair passing to the tube 33 from the tube 34 and airopenings 33a and, as

a result, a column of liquid fuel in tube 33 cannot be built up to sucha height as to seal 'olf the air openings 33a.. The combustible mixtureformed by the compressed air issuing from tank 14 and the liquidfuel'from tank 14v causes the burner 25 to operate for a short time,such asa few seconds, until vaporizing tube 25?) is heated. As soon astube 25?) becomes thoroughly heated, any fuel supplied to this tube inliquid form will readily vaporize. As the vaporizing tube 256 becomesheated therefore, the mixture running through this tube will vaporizeand will expand to many times its original 4volume, thereby creating aback pressure in conduit 30 and tube 33. This back pressure slows downthe movement of the air in tube 33and thereby permits a greater quantityof liquid fuel from the liquid space in the tank 14 -to travelthroughthe passage in plug 35 to the tube The proportion of liquid fuelrelative to compressed air in the tube 33 is therefore increased 'due tothe back pressure caused by the vaporized gases in the vanorizing tube256. It is found, however, that the liquid fuel or gasoline will notrise in the tube 33in sufficient quantity to completely seal off thesupply of air to the tube 33 and, as a result, small quantities of airusually in bubble form will travel from the top of the tank 14 throughtube air openings 33a and tube 33 to the vaporizing tube 255 as long asthe burner 25 remains in operation without enlarging the liquid fuelpassage into the tube 33. In other words, if the burner 25 ismaintained-in continuous operation, the air supply in tank 14 will becontinuously depleted if the liquid fuel passage tothe tube 33 remainsof the same small size necessary for use to supply the requisiteproportions of liquid fuel and air to the tube 33 for initial ignitionof the burner Q5 for starting when the vaporizing tube 25.7) is cold.

As'soon as vaporizing tube Q57) becomes thoroughly heat-ed` the wheel 39is turned to carry valve 38a high above its seat, and at the same timeto carry needle 380 either upwardly into the enlarged portion of theopening in plug 35 or completely7 above and out of the opening. As theneedle 380 is cfarried into the enlarged portion of the opening of plug35 above the lower tapered portion thereof, or as the needle 330 iscarried completely out of this opening, the passa ge through the openingfor the travel of liquid fuel from the fuel space in the tank 14 to thetube 33 is greatly enlarged. As a result, the major part of thefrictional resistance hitherto offered to the travel of liquid fuel fromthe fuel space in the tank to the tube 33 through theopening in plug 35will be eliminated and the liquid fuel will quickly run into the tube 33to seal the openings 33a completely and to cause the rise of liquid fuelin the annular space be-1 tween tube 34 andy 33 to lapproximately thesame level as the level of liquid fuel in the tank 14. It will then beno longer possible n for compressed air to travel from the top of thetank 14 through tube 34 and openingsf33a to tube 33 and nothing butliquid fuel will pass through tube 33 and conduit 30 to the vaporizingtube 256. In other words, the burner 35 may be operated indefinitelywithout depleting the supply of compressed air in tank 14.

Although the burner 25 is complete in itself and can be operated for anydesired length of time, in the embodiment shown, this burner is utilizedchiefly for heating the main vaporizing tube 19 which supplies the mainburner 16. Accordingly, after the burner 25 has been in operation for ashort time, such as a minute, the main vaporizing tube 19 will becomeheated whereupon the va ve controlled by the wheel 2O may be opened andthe main burner 16 may be lit. Fuel admitted to main vaporizing tube 19will be vaporized and will pass to mixing chamber 17 from whence thecombustible mixture will pass to main burner 16. After main burner 16 isplaced in operat-ion, valve 38a may be closed by turning the wheel 39 toplace burner 25 out of operation. Also, if desired, valve 27 may also beclosed, although this is not necessary. It will, of course, be seen thatthe opening in plug 35 will be kept clear at all times, due to themovement of the needle 380 through this opening.

lVhen the valve 38a is first opened for the initial starting of theburner 25 by turning the wheel 39 about half a turn, (valve 2T beingconsidered to be opened) a small quantity of liquid fuel will be firstdischarged from the vaporizing tube 256 into the burner 25 before thecombustible mixture of air and liquid fuel supplied for instant lightingis discharged from the vaporizing tube. This discharge of a smallquantity of liquid fuel is due to the fact that when the valve 38a isfirst opened, quite a large quantity of liquid fuel will stand in thetube 33 and this liquid fuel must move upwardly out of the tube 33beforethe compressed air charged with liquid fuel is supplied to thevaporizing tube 256. This liquid fuel initially discharged from thevaporizing tube 255 will be caught and held in a small recess formed inthe burner 25 immediately below the outlet 250 where the liquid fuelwill gradually be heated and vaporized when the burner is lit.

In Fig. 5, a modified form of the invention is shown in which a plug 42is threaded into the bottom of the tube 33, the opening in plug 42 beingtapered at its lower portion. Plug 42 has a cylindrical opening at itslower end in which is seated a semi-spherical screen 43,'the same beingheld in place by a small ring 44 pressed into member 42. The stem 38 hasits lower end portion projecting into the opening 42a in plug 42 and ithas the reduced portion 380 adapted to extend through the opening 42a..The operation of the device shown in Fig. 5 is similar to that alreadydescribed and this operationneed not be further repeated.

From the above description, it is seen that applicants have provided avery simple and efficient instant lighter structure for hydrocarbonburning devices, such as stoves, lanterns, irons, heaters etc. Althoughthe nection with a stove, its application to other devices than stovesutilizing a hydrocarbon fuel which is vaporized before being burned, isdeemed obvious. It will be understood, that if desired, the burner 25can be used as the main burner for the hydrocarbon burning device orthat if desired, thc vaporizing Atube 25?) can be connected with anysuitable type of mixing chambefand burner. lVith the starting structuredescribed, used in connection with a burner, such as the burner 25, orany other suitable type of burner, it is unnecessary to preheat t-hevaporizing tube by use of a priming cup or by a torch before the burneris lit and yet the burner can be 1naintained in constant operation afterbeing lit without rapidly depleting the compressed air in the tanksupplying the burner. The starter structure has been amply demonstratedin actual practice, and has been found to be successful and efficient.

It will, of course, be understood that various changes may be made inthe form, de-y tails, arrangement and proportions of the parts withoutdeparting from the scope of applicants invention, which generallystated, consists in a device capable of carrying out the objects' aboveset forth and in the novel parts and novel combinations of partsdisclosed and defined in the appended claims.

What is claimed is 1. The combination with a device using liquidvaporizing fuel having one or more main burners, a fuel tank adapted tocontain fuel under air pressure and a Vaporizing member connecting saidfuel tank and burners, of an auxiliary burner for heating saidvaporizing member, a conduit connecting said auxiliary burner and thetop of said fuel tank, comprising al tube extending downwardly into theliquid fuel space in said tank and having a small opening at its lowerend for communication with said fuel, a second tube surrounding saidfirst mentioned tube and forming therewith an annular space, the upperend of said annular space being open and disposed in the air space insaid fuel tank and the lower end of said annular space being closed,said annular space communicating with the interior of the firstmentioned tube near the lower end thereof, and a valve for controllingsaid first mentioned tube.

2. The combination with a device using liquid vaporizing fuel having oneor more main burners, a fuel tank adapted to contain fuel under airpressure, and a Vaporizrlighter structure has been described in coningmember connecting said fuel `tank and burners, of an auxiliary burnerfor heating adapted to extend through said opening at the bottom of saidtube and a second tube surrounding said first mentioned tube and formingtherewith an annular space, the upper end of said annular space beingopen and disposed in the air space in said fuel tank and the lower endof said annular space being closed, said annular space communicatingwith the interior of the first ment-ioned tube near the lower endthereof.

3. The combination with a device using liquid vaporizing fuel having oneor more main burners, a fuel tank adapted to contain fuel under airpressure and a vaporizing member` connecting said fuel tank and burners7of an auxiliary burner for heating said vaporizing member, a conduitextending from said auxiliary burner, a valve fixture connecte ed to thetop lof said fueltank to which said conduit is connected, a tube securedto said xture and extending down into the fuel space in said tank, amember secured to the lower end of said tube having a small openingtherethrough, a shell surrounding said member having a screen givingaccess to said member and opening, a second tube surrounding said firstmentioned tube and forming therewith an annular space, the upper end ofsaid annular space being open and disposed in the air space in said fueltank, and the lower end of said annular space being closed, said annularspace communicating with the interior of the first mentioned tube nearthe lower end thereof, a valve in said valve body having a stemextending downwardly through said first mentioned tube and the member atthe lower end thereof, and having a reduced portion extending into theopening in said member.

4. ln a device using liquid vaporizing fuel and having a fuel tankadapted to contain liquid fuel under air pressure, a vaporizing memberand a burner for heating said vaporizing member, a valve member, aconduit connected to said burner and to said valve member, a tubeextending from said valve member downwardly into the fuel space in saidtank and having an inlet opening adjacent its lower end for fuel toenter the same, said valve member being adapted to close and opencommunication between said tube and conduit, a second tube surroundingsaid first mentioned tube and forming therewith an annular space, theupper end of vsaid annular space being open and being disposed in theair space in said fuel tank, and the lower end of said annular spacebeing closed, said annular space communicating with the interior of thefirst mentioned tube near the lower end thereof, whereby a mixture ofair and vaporizing fuel may pass through said iirst mentioned tube andconduit to said burner from said tank.

5. In a device using liquid vaporizing lfuel and having a fuel tankadapted to contain fuel under air pressure, a vaporizing member andaburner for heating said vaporizing member, avalvemembersecuredto saidtank, a conduit connected tol said valvemember and extending to saidburner, a tube connected to said valve member and extending downwardlyinto the fuel space in said tank and having an opening at its lower endfor communication with the fuel in said tank, a valve in said valvemember for opening and closing communication between said tube andconduit, and having a stem projecting downwardly into said tube having aportion adapted to move through the opening in the lower end of saidtube to clear the same, a second tube surrounding said first mentionedtube and forming therewith l an annular space, the upper end of saidannular Space being open and disposed in the air space in said fueltank, and the lower'end of said annular space being closed, said annularspace communicating with the interior of the first mentioned tube nearthe lower end thereof, whereby a mixture of fuel and air may passthrough `said tube and conduit to said burner. h

6. A fuel supply device for the starter of a liquid fuel stove, ysaiddevice comprising a valve fitting adapted to be mounted in the top of aliquid fuel tank, a tube connected to and extending downwardly from saidfitting, ysaid tube having a transverse opening therein near its lowerend', a sleeve surrounding said tube in spaced relation thereto andjoined to said tube below said opening, said sleeve terminating short ofthe upper end of the tube, and means forming a restricted aperture atthe lower end of said tube through which liquid may pass slowly intosaid tube and sleeve.

7. In a device using liquid vaporizing fuel, a fuel tank adapted tocontain liquid fuel under air pressure, a burner, a vaporizing membersupplying said burner and on which said burner plays when in operation,a tube running into the liquid fuel space of said tank and having anopening located in said'fuel space, means sealed from the liquid fuelspace of said tank and affording communication between the air space ofsaid tank and said tube adjacent said opening, means aordingcommunication between said tube and said vaporizing member and meanscontrollable from outside said tank for restricting the lll@ passagethrough said opening and for suddenly enlarging the passagetherethrough.

8. In a device using liquid vaporizing fuel, a fuel tank adapted tocontain liquid fuel under air pressure, a burner, a vaporizing membersupplying said burner and on which said burner plays when in operation,a tube running into the liquid Jfuel space of said tank and having anopening located in said fuel space, means sealed from the liquid fuelspace of said tank and aii'ording communication between the air space ofsaid tank and said tube adjacent said opening, means afordingcommnication between said tube and said vaporizing member, a Valvecontrolling the passage through said tube, and means operable With saidvalve for restricting the passage through said opening when said valveis opened but slightly and for suddenly enlarging the passage throughsaid opening when said valve is Widely opened.

In testimony whereof We almx our signatures.

WALTER OLSEN. SOPHUS RASMUSSEN.

